Roasted Peppers in Olive Oil: The Method, Storage and Safety
Roasted red peppers in olive oil are one of the simplest things you can make at home: peppers charred until the skins blister, peeled, sliced and covered in good extra virgin olive oil. They are also one of the few home recipes where storage is a genuine safety question. Peppers are a low-acid vegetable, and covering them in oil shuts out air, which is the condition in which the bacterium behind botulism can grow. So below you will find our own method, written from scratch for this article in metric and US measures, followed by the part most recipes skip: how to store them safely, based on Oregon State University Extension and published food-safety research. The short version is fridge, four days, or freezer, and never the cupboard.
For our own oil, see our Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml).
The Short Answer
- Roast whole red peppers at 230°C / 210°C fan / 450°F for 30–40 minutes, turning once, until the skins are blistered and blackened in patches; steam them in a covered bowl for 15 minutes, then peel, seed and slice.
- Dress about 450g (1lb) of peeled peppers with 60ml (¼ cup) of extra virgin olive oil, 1 tablespoon of red wine vinegar, salt and herbs, and keep them in a clean, covered container in the fridge.
- Oregon State University Extension advises that home-made vegetables or herbs in oil be refrigerated and used within 4 days, or frozen for longer storage.
- Never store home-made roasted peppers in oil at room temperature: the oil creates an oxygen-free environment in which Clostridium botulinum can grow and produce toxin, and you cannot see, smell or taste it.
- A splash of vinegar adds flavour but does not make the jar shelf-stable; only tested acidification methods, followed exactly, do that, and shop-bought jars are processed to a commercial standard.
- To keep them longer, freeze the peppers in their oil in small portions, then thaw in the fridge.
- Sidr & Stone's olive oil is a single-estate, cold-pressed, unfiltered extra virgin olive oil from our own farm on the plains outside Marrakech, Morocco, sold in 500ml dark glass.
Roasted Peppers in Olive Oil: Ingredients
This makes about 450g (1lb) of peeled, sliced peppers, enough to fill a 500ml (2-cup) container with their oil, or to serve four as part of a spread. It is deliberately a batch you can finish within four days.
| Ingredient | Metric | US | Notes |
|---|---|---|---|
| Large red bell peppers (or a mix of red, yellow and orange) | 4, about 800g in total | 4, about 1¾lb in total | Thick-walled, heavy peppers peel more easily |
| Extra virgin olive oil, plus 1 tsp for roasting | 60ml | ¼ cup | Add more to cover if you prefer them submerged |
| Red wine vinegar or sherry vinegar | 1 tbsp (15ml) | 1 tbsp | For flavour; it does not make them shelf-stable |
| Fine sea salt | ½ tsp (about 3g) | ½ tsp | To taste |
| Garlic clove, thinly sliced (optional) | 1 | 1 | Same 4-day rule applies |
| Fresh basil leaves or a pinch of dried oregano | a handful / ½ tsp | a handful / ½ tsp | Add basil just before serving |
Method: How to Roast and Peel Peppers, Step by Step
- Heat the oven. Set it to 230°C conventional, 210°C fan, 450°F or gas mark 8. Line a baking tray with foil or baking paper.
- Prepare the peppers. Wash and dry them and leave them whole. Rub them all over with a teaspoon of olive oil, which helps the skin blister evenly rather than drying to leather.
- Roast. Roast for 30–40 minutes, turning them with tongs halfway, until the skins are wrinkled, puffed away from the flesh and blackened in patches, and the peppers have collapsed slightly.
- Steam. Tip them straight into a heatproof bowl, cover with a plate or a lid, and leave for 15 minutes. The trapped steam loosens the skins.
- Peel and seed. When cool enough to handle, pull off the skins, then open each pepper, pull out the stalk and seeds and scrape away any stray seeds. Do not rinse them under the tap; it washes away the sweet, smoky juices. Save those juices in the bowl.
- Slice and dress. Cut the flesh into strips about 2cm (¾in) wide. Toss with the oil, vinegar, salt, garlic if using, oregano and a spoonful of the saved juices.
- Chill promptly. Pack into a clean glass container, press the peppers down so the oil rises around them, cover and refrigerate as soon as they are cool, and within 2 hours of peeling. Label the container with the date and the date four days later.
You can roast them other ways. Directly over a gas flame, turning with tongs, takes 8–12 minutes and gives the smokiest flavour. Under a hot grill (broiler), about 10cm (4in) from the element, takes 15–20 minutes, turning every few minutes. On an outdoor barbecue over high heat, 10–15 minutes. In an air fryer at 200°C (400°F), halved peppers take about 15–20 minutes. Whatever the method, you are aiming for blackened, blistered skin and soft flesh, not ash.
How to Store Roasted Peppers in Olive Oil Safely
This is the section that matters most. Home-made roasted peppers in olive oil should be kept in the fridge at 5°C (41°F) or below and eaten within 4 days, or frozen for longer storage. That is the guidance in Oregon State University Extension's publication Herbs and Vegetables in Oil (SP 50-701, revised January 2025), which advises that fresh vegetables or herbs in oil be used within 4 days or frozen, and that home-made flavoured oils be stored in the fridge for up to 4 days.
Why oil makes storage a safety issue
Clostridium botulinum, the bacterium that produces botulinum toxin, lives as spores in soil and can be carried on vegetables and herbs. Its spores do not grow in air, but they can grow in moist, low-acid, oxygen-free conditions, and oil poured over a vegetable creates exactly that. Peppers are low-acid, and the spores survive ordinary cooking: Penn State Extension notes they can survive the boiling point of water and are destroyed only at about 116°C (240°F), a temperature reached in a pressure canner, not inside a roasting pepper, whose moisture holds it near 100°C. Garlic and herbs add more risk. A review in Food Protection Trends by Nummer, Schaffner, Fraser and Andress (2011) found that most documented botulism outbreaks from vegetables and herbs in oil involved home-prepared products, with peppers, garlic, mushrooms and eggplant among the foods implicated. The same review is blunt about the warning signs: there may not be any, because appearance and smell are not reliable indicators.
The rules, in one table
| Where | How long | What the guidance says |
|---|---|---|
| Room temperature, cupboard or counter | Never for storage; no more than 2 hours out of the fridge while serving (1 hour above 32°C / 90°F) | Room temperature is the ideal condition for botulism to develop in low-acid foods under oil (UMN Extension); the 2-hour rule is the general US guidance for perishable food (FoodSafety.gov) |
| Fridge at 5°C (41°F) or below | Up to 4 days | Oregon State University Extension SP 50-701; Nummer et al., 2011, who advise keeping the fridge at or below 3.3°C (38°F) |
| Freezer at −18°C (0°F) | For longer storage | "The safest recommendation is to freeze" vegetables or herbs stored in oil (Nummer et al., 2011) |
| Shop-bought jar, unopened | As the label says | Commercial jars are acidified and heat-processed under controlled conditions so they can be sold shelf-stable |
| Shop-bought jar, opened | As the label says, usually in the fridge | Follow the manufacturer's "refrigerate after opening" instruction |
A note on fridge temperatures, because they vary by country: the UK Food Standards Agency advises setting your fridge between 0 and 5°C, the US FoodSafety.gov charts say 40°F (4°C) or below, and Health Canada says 4°C (40°F) or lower. A cheap fridge thermometer is worth having if you make these often.
How to freeze roasted peppers in oil
Freeze them in small portions so you only thaw what you will eat in a day or two. Spoon the dressed peppers and their oil into an ice-cube tray or small freezer bags, freeze flat, then pack into an airtight container. Oregon State's guidance suggests the same ice-cube-tray approach for crushed vegetables and herbs. Thaw portions in the fridge, not on the counter, and treat thawed peppers like fresh: eat within the same short window. Freezing softens the texture a little, which makes them best for pasta, sauces, soups and dips rather than antipasto.
The objection: "My family kept peppers in oil in the pantry for months"
Plenty of people have, and plenty of popular recipes still suggest keeping home-made peppers in oil for weeks or months. Botulism is rare, and most jars that sit in a cupboard never cause harm. But the honest point is that rare and serious is not the same as safe: the toxin can cause severe illness and gives no warning you can see or smell, and Extension guidance is written around that risk. Traditional pantry methods often relied on far more vinegar or salt, or on proper heat processing, than a simple jar of peppers in oil. Our advice is the conservative one: four days in the fridge, or freeze.
The objection: "Can't I just can them, or add more vinegar?"
Not with a recipe like this one. Oregon State University Extension notes that commercial garlic-in-oil products are acidified to prevent bacterial growth, and that research-based acidification procedures exist for only a few herbs and vegetables, which "must be followed exactly". The 2011 Food Protection Trends review concluded that acidification, boiling-water canning and similar steps need more research before they can be recommended for home-prepared vegetables in oil. A tablespoon of vinegar in a bowl of peppers is seasoning, not preservation. If you want peppers in the cupboard, buy a commercially processed jar, or follow a tested pickled-pepper recipe from a recognised home-preserving authority exactly, and keep this recipe for the fridge.
Which Olive Oil to Use for Roasted Peppers
Use extra virgin olive oil. Here the oil is not cooked at all after the peppers are roasted: it is the dressing, so its flavour is the point. A fruity, slightly peppery extra virgin oil suits sweet, smoky peppers well, and a robust one stands up to garlic and chilli.
- Do not heat the oil to "preserve" the peppers. Some recipes pour hot oil over the jar. Heating the oil does not make the jar safe to keep at room temperature, and it dulls the oil's fresh flavour.
- Expect the oil to cloud and thicken in the fridge. Extra virgin olive oil turns cloudy and partly solid when chilled. That is normal and harmless; leave the container out for 15–20 minutes before serving, then put it straight back in the fridge.
- Choose fresh oil. Rancid oil smells of crayons or putty, and in a raw dressing you will taste every bit of it. Our guide to choosing a quality olive oil covers what to check on the bottle.
The same fridge-and-four-days rule applies to other home-made flavoured oils, which is why our guides to garlic infused olive oil and infused olive oil set out the safe methods for each. If you are using hot peppers, our article on chili olive oil covers the chilli side.
Variations: Hot Peppers, Banana Peppers and Sweet Mini Peppers
The method works for most peppers; only the timing and the peeling change. The storage rules do not change at all.
- Yellow and orange bell peppers: roast exactly as above; they are slightly sweeter and peel just as easily. A mix of colours looks best on a platter.
- Sweet mini peppers: roast whole at the same temperature for 15–20 minutes. Their skins are thin, so many people do not bother peeling them; just pull off the stalks.
- Banana peppers and other thin-walled peppers: roast or grill for 10–15 minutes until blistered. Peeling is optional; the skin is tender.
- Hot peppers (jalapeño, Fresno, poblano): roast or char until blistered, wear gloves to peel and seed them, and use them sparingly in the dressing alongside sweet peppers. Poblanos peel well; small chillies are better left unpeeled.
- With garlic: thinly slice raw garlic into the dressing, or roast a few whole cloves alongside the peppers for a mellower flavour. Garlic is one of the foods most often linked to botulism in oil, so the 4-day fridge rule is non-negotiable.
How to Use Roasted Peppers in Olive Oil
A container of roasted peppers in the fridge turns quick meals into good ones over the four days you have to eat them.
- Antipasto and mezze: with olives, cheese, good bread and a few basil leaves.
- Sandwiches and toasties: layered into a sandwich or our olive oil grilled cheese; pat them dry first so the bread does not steam.
- Pasta and grains: tossed through hot pasta with their oil, a little garlic and parsley, or stirred into couscous and rice.
- Dips and spreads: blended with toasted walnuts, breadcrumbs and a little chilli for a muhammara-style dip, or with chickpeas for a red pepper hummus.
- Eggs and tray bakes: folded into an omelette or shakshuka, or added in the last minutes to roast vegetables; our olive oil roast potatoes are a natural partner.
On health, the honest framing is short. Red peppers are a vegetable rich in vitamin C and carotenoids, and dressing them in extra virgin olive oil is a typical Mediterranean way to eat them. That makes them a good everyday food, not a treatment for anything.
Why Sidr & Stone
In roasted peppers, the olive oil is never cooked after the peppers come out of the oven: it is the dressing, tasted raw in every strip. That is where an oil's freshness and origin show, and it is the part of this recipe we can speak for. Sidr & Stone's extra virgin olive oil comes from one place, our own farm on the plains outside Marrakech, and we control every step from tree to bottle.
- Single-estate: Sidr & Stone's olive oil comes from our own family-owned farm near Marrakech, Morocco, with no blending across origins.
- Rain-fed: the trees are not irrigated; they take what the season gives.
- Organically grown: no synthetic fertilisers, pesticides or herbicides are used (not yet certified; certification is in progress).
- Single harvest: each batch is small and limited, picked when the fruit is ready; once it is gone, it is gone until the next harvest.
- Cold-pressed within hours of harvest: to protect flavour, aroma and polyphenols.
- Unfiltered extra virgin: minimally processed, so a little natural sediment at the bottom of the bottle is normal.
- 100% natural: a single ingredient, olive oil, with nothing added.
- Dark glass with a gold label: 500ml bottles that protect the oil from light.
- 10% of profits to charity: a Sidr & Stone commitment across every product.
- Fulfilment in the UK, EU and US.
We will not tell you ours is the best olive oil for roasted peppers; your own taste is the judge of that. What we will say is that it is single-estate Moroccan, rain-fed, organically grown and cold-pressed within hours of harvest. A sealed bottle of olive oil keeps in the cupboard; the peppers you dress with it belong in the fridge.
Frequently Asked Questions
How long can you keep roasted peppers in olive oil?
Home-made roasted peppers in olive oil should be kept in the fridge at 5°C (41°F) or below and eaten within 4 days, as Oregon State University Extension advises for home-made vegetables in oil. For longer storage, freeze them in small portions.
Why can't roasted peppers in oil be kept at room temperature?
Peppers are low-acid, and oil shuts out air, creating the moist, oxygen-free conditions in which Clostridium botulinum spores can grow and produce toxin. The toxin gives no reliable warning in look or smell, so home-made jars must stay cold.
How do I can roasted red peppers in olive oil?
There is no research-tested way to can a recipe like this at home, and a published food-safety review concluded that acidification and canning of home-prepared vegetables in oil need more research before they can be recommended. Keep home-made peppers in oil in the fridge for up to 4 days or freeze them.
Do you put oil on peppers before roasting?
A light rub of oil, about a teaspoon for four peppers, helps the skins blister evenly. It is optional; the peppers will char without it, but the skins can dry and stick.
Is Sidr & Stone's olive oil good for roasted peppers?
Yes. It is a single-estate, cold-pressed, unfiltered extra virgin olive oil, so it works well as a raw dressing where its flavour shows. Use it straight from the bottle; there is no need to heat it.
Does adding vinegar make roasted peppers in oil last longer?
Not safely. A tablespoon of vinegar adds flavour but does not acidify the peppers enough to prevent botulism. The 4-day fridge limit still applies unless you follow a tested acidification or pickling procedure exactly.
Where can I buy single-estate extra virgin olive oil?
Our Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml) is available directly from the Sidr & Stone website, with fulfilment in the UK, EU and US.
Is olive oil a medicine?
No. Olive oil is a food, not a medicine. It has a long traditional history — including being honoured in the Prophetic Sunnah — and a substantial body of modern research, particularly around polyphenols, cardiovascular health, and the Mediterranean diet pattern. It can be a worthwhile part of a healthy routine, but it does not cure diseases and is not a substitute for medical care. Be cautious of any olive oil marketed with specific disease-cure claims.
Final Thoughts
Roasted peppers in olive oil take an hour, mostly hands-off, and reward you with something sweet, smoky and silky that improves almost anything it touches. The method is easy: roast hot, steam, peel without rinsing, dress with good oil. The part worth taking seriously is the storage, because a jar of low-acid vegetables under oil is exactly where botulism can develop. Make a batch you will eat within four days, keep it in the fridge at 5°C (41°F) or below, freeze any you will not get through, and never leave a home-made jar in the cupboard. Do that, and the only thing to think about is which olive oil you want to taste.
If you want an oil with a clear origin for dressing them, our Cold-Pressed Single-Estate Extra Virgin Olive Oil - Marrakech (500ml), single-estate, rain-fed and cold-pressed within hours of harvest, is available to pre-order now, with fulfilment in the UK, EU and US.
Our extra virgin olive oil is grown organically on our own single-estate farm on the plains outside Marrakech: we control every step from tree to bottle, and no synthetic pesticides, herbicides or fertilisers are used. It is not yet certified organic — certification is in progress, and we will publish it as soon as it comes through.
Disclaimer: This article shares a home-cooking recipe and general food-safety information at the time of writing, based on Oregon State University Extension, Penn State Extension, University of Minnesota Extension, the US CDC, Health Canada, the UK Food Standards Agency, FoodSafety.gov and a peer-reviewed review in Food Protection Trends; guidance can change, so check your national food-safety authority. Home-made vegetables in oil must be refrigerated and used within 4 days or frozen; never store them at room temperature. Botulism is a medical emergency: if you have symptoms such as blurred or double vision, drooping eyelids, slurred speech, muscle weakness or difficulty swallowing or breathing, the US CDC advises going to a doctor or emergency room immediately. References to other organisations imply no affiliation or endorsement. Olive oil is a food, not a medicine, and is not a substitute for medical treatment of any condition. For any health concern, consult a qualified medical professional.